Update sketch.json

sketch.json

@@ -51,6 +51,6 @@
     "commercial_support_available": "Yes",
     "wikipedia_url": "https://en.wikipedia.org/wiki/Sketch_(software)",
     "reference_list": [],
-    "success_case_list": []
+    "success_case_list": ["https://www.sketch.com/blog/made-with-sketch/"]
   }]
 }